Sander with improved feed mechanism

ABSTRACT

Apparatus for sanding or otherwise removing material from the rear surface of an ornamented frame, panel or the like to make said rear surface plane and flat. The feed works for the work pieces comprise a multiplicity of individually mounted feeding and holddown members adapted to engage the front, ornamented face of the work piece and feed the rear surface into contact with a sanding drum or the like.

United States Patent 11 1 CulleyrJrt 1451 Nov. 12, 1974 [541 SANDER WITH IMPROVED FEED 1.495.816 5/1924 Smith 198/170 MECHANISM 1.533.353 4/1925 Smith 193 170 lnventor: Donnell H. Culley, .lr., PO. Box 1581. Morristown, Tenn. 37814 Filed: Aug. 9, 1973 1 Appl. No: 387,142

1 U.S. Cl. 198/168, 51/76 R, 51/215 E,

I 198/170 [51] Int. Cl. 865g 19/00, 1324b 47/20 [58] Field of Search 51/61, 76 R, 138, 215 E, 51/215 M;144/117, 128 R, 245; 198/170, 160, 162, 184, 168

[56] References Cited UNITED STATES PATENTS 1,249,533 12/1917 Smith 198/170 Primary Examiner-Othell M. Simpson Attorney, Agenl, 0r I"irm-.Icnnings, Carter & Thompson 1 1 ABSTRACT Apparatus for sanding or otherwise removing material from the rear surface of an ornamented, frame, panel or the like to make said rear surface plane and flat. The feed works for the work pieces comprise a multiplicity of individually mounted feeding and holddown members adapted to engage the front, ornamented face of the work piece and feed the rear surface into contact with a sanding drum or the like.

4 Claims, 12 Drawing Figures PATENIEDNBV 121924 1 SANDER WITH IMPROVED FEEDMECHANISM This invention relates to sanding apparatus for parts, especially plastic parts such as ornate picture frames, headboards for beds, drawer fronts, tops for small tables and the like.

In that art to which my invention relates it is now customary, particularly in furniture manufacture, to provide many parts, cast of the various plastic materials such as polyurethane, polyethylene and the like and heavily ornamentedon one surface. In the manufacture of these parts it is customary to cast them in molds of silicone rubber or like material, the ornate surface being provided by such mold. This is done simply by filling the mold with the semi-liquid material and permitting it to harden. This results in parts having front surfaces of which are ornate as desired, but the back surfaces are irregular in the sense that they are not completely plane. In other words, such as-cast parts, while perfectly satisfactory on the ornate side, have wavy rearsurfaces which are unsuitable for attachment to supporting structures such as reinforcing frames, boards, or the like. Therefore, before such parts can be used it is necessary to flatten or make coplanar the entire back surface so that the part may be glued or otherwisesecured in flat, engaging relationship to the surface of a supporting reinforcing or supporting member, thus to incorporate it into the piece of furniture desired.

Several methods have been proposed to make plane the rear surfaces of such parts. Generally, one of the most accepted methods is to provide a jig which will support the piece, ornate surface down, and to pass the a piece while supported in the jig beneath sanding rollers or drums. This necessitates the recirculation of the jigs in the system,resulting in very high labor costs because of the time involved in making the set up for each piece. Furthermore, the accuracy of such jigs leaves much to be desired because of the inherent difficulties of placing the ornate side of the piece in proper relation to the supporting jig.

Another method recently introduced to the market is a drum sander which has a feed for engaging the ornate side of the parts. This feed consists of a plurality of air bags mounted for traveling fashion much in the manner of 'abelt, these air bags being supposed to engage the ornate surface of the piece whereby its opposite side is fed into contact with the rotatingsanding drum, thus to smooth and make plane such surface. This apparatus is veryunreliable, primarily due to leakage in the air bags themselves and has not proven to be very satisfactory.-

In view of all the foregoing an object of my invention is to provide a machine for smoothing and making plane the rear surfaces of ornate parts as describedabove, which apparatus shall comprise a rotary sanding drum" or the like together with feed means especially adapted mechanically to engage the ornate surface of the part and topropel it through: the apparatus, holding it firmly and. accurately into contact with the' sanding drum.

More in detail, my improved apparatus comprisesa rotary sanding. drum in" length at least equal to thewidth of the piece to be sanded. The drum isplaced in"- termediate the ends. of two table sections, the infeed one of which is adjustable for height so as to regulate thedepth of the cut taken by the sanding. drum on the surface of the partfed therethrough. Operating overa head is my improved feeding mechanism for engaging,

propelling and holding the parts down. This feed mechanism may comprise a pair of transversely spaced chains, passing over suitable driven and supporting sprockets and having a multitude of individually operable, spring pressed feet, preferably carrying pad-like members of friction material for engaging the piece to be sanded. Based upon my investigations the details concerning the individually mounted part engaging feed are very important to the successful feeding of these parts andithis will be brought out more in detail as this description proceeds.

Apparatus illustrating features of my invention is shown in the accompanying drawings forming a part of this application in which:

FIG. 1 is a side elevational view with certain parts broken away and in section;

FIG. 2 is an enlarged detail sectional view taken generally along line 2-2 of FIG. 1; a

FIG. 3 is a plan view with certain parts broken away and in section;

FIG. 4 is a bottom view with parts broken away, the

view being taken generally along line 4-4 of .FIG. 1;

FIG. 5 is an enlarged detail elevational view of one of the supporting jacks and elevating mechanism as viewed in the direction of arrows 55, FIG. 2;

FIG. 6 is an enlarged detail sectional view taken generally along line 6-6 of FIG. 5; j

FIG. 7 is an enlarged detail fragmental view taken generally along line 7-7 of FIG. 1;

FIG. 8 is an enlarged detail sectional view of one of the individually mounted feed assemblies and their sup.- porting structure;

FIG. 9 is a view taken generally along line 99 of FIG. 8;

FIG. 10 is an enlarged detail sectional view taken generallly along line 10-10 of FIG. 4 and showing a suitable fonn of arbor for supporting the sanding drum which may be employed with my improved apparatus;

FIG. 11 is a detail fragmental sectional view taken generally along line 11-11 of FIG. 10; and,

FIG. 12 is an end elevational view of the arbor as viewed in the direction of arrows l212 of FIG. 10.,

Referring now to the drawings for a better under standing of my invention it will be seen that the same embodies side frame members) and 11 which may be pandingtype which supports a replaceable sanding drum indicated at 16:

The sanding drum is locatedat the inner end of an infeed table 17. The infeed table is supported betweenthe frame members 10 and 11 by means-of ways 18 which fit slidably in U-shaped guides 19, shown'in-detail in FIG. 7. In other words, the table 17 issupported so that when actuated by the screw mechanism presently to be described it raises and lowers relative to the sanding drum 16, thus to regulate the depth of cut.

Mounted in a suitable bearing 21 secured to a cross member 22 extending between the head and 11 is an operating screw 23 for the table 17. At its lower end the screw 23 carries an operating handle 24 and upwardly from the bearing 21 a sprocket 26 is fast on the screw 23. The upper end of the screw is threaded as indicated at 27 into a cross piece 28 extending between the downturned flanges 17a of the table 17.

A sprocket chain 29 passes over the sprocket 26 and over a similar sprocket 31 carried on a screw 23a, similarly mounted in a bearing 21a and having a similarly threaded end 27a. Therefore, by manual rotation of the handle 24 both screws are rotated in unison, whereby the table 17 is caused to move upwardly or downv wardly, this being due to the supports 18-19 as explained. By this means the depth of cut of the parts being passed through the apparatus may be regulated.

Rearwardly in the sense of flow of material from the sanding drum is a fixed outfeed table indicated generparatus indicated generally in the drawings by the nu- I meral-33.

First, the feed section 33 comprises a pair of side plates 34 and 36 suitably cross braced by several members such for instance as a cover plate 37, FIG. 2 and end plate 38, FIG. 1, and several internal cross members, the latter of which have been omitted from the drawings for the sake of clarity. Suffice it to say that the entire unit 33 is suitablybraced to form a rigid, heavy duty section for supporting theparts to be later described. I

In order to accommodate work pieces of different thicknesses, the entire section 33 is adapted to be raised and lowered relative to the tables 32 and 17. To

this end I mounted on brackets 39, outstanding from the sides of the main frames plates 10 and 11, four vertically disposed jack' screws 41. The screws 41 are mounted at their lower ends non-rotatably in brackets '39. I l Mounted on the sides of the plates 34 and 36 are outwheel 51 whichrnay be calibrated in inches or the like. Also, the cross shafts 48 may be'tied together by a chain 52 passing over sprockets 53 and 54 carried by the shafts 48. Thus, through the means shown when the hand wheel 51 is rotated the entire upper assembly 33 is raised and lowered relative to the tables 32 and 17.

Extending across the plates 34 and 36 of the section 33 is a shaft 56 suitably supported in bearings 57 mounted on the outer surfaces of the plates 34 and 36. A second shaft 58 is mounted in bearings 59 in turn journaled in take up units 61. In other words, the shafts 59 may be adjusted fore and aft of the section 33 of the apparatus for a purpose presently to appear.

Mounted non-rotatably on the shaft 56, inwardly of the plates 34 and 36 are sprockets 62. In similar manner, non-rotatably mounted on the shaft 58 just inwardly of the plates 34 and 36 are sprockets 63. Passing over the sprockets are chains 64 which extend substantially the full length of the section 33 as illustrated particularly in FIG. 1 of the drawings.

As best shown in FIGS. 8 and 9 the chains carry what are known in the trade as K type attachments indicated at 66. Essentially, these are L-shaped bracket members which are secured to the chain with one leg projecting horizontally, inwardly of the chains. Mounted on the attachments and extending from chain to chain are cross members 67 in the form of flat plates. Spaced from the bar 67 are other cross bars 68 and the bars 67 and 68 are tied together at the ends by means of plates 69. Therefore, secured to and spanning between the chains are a plurality of the plates 67, 68 and tie plates 69 which form relatively rigid units mounted by the attachments 66 to the chains.

Carried by each of the sets of plates just described is a plurality of individually operable holddown and driving members for engaging the ornate surface of the parts to be passed through the apparatus. Thus, each of these units may be made of a piece of L-shaped plate 71, the free end of its leg 72 lying closely alongside the edge of the plate 67. See FIG. 8. The other leg 73 of the member 71 has secured thereto as by welding a length of tube 74. Also secured to the surface of the leg 73 of the member 71 is a rod 75. A compression spring 76 surrounds the rod and is held in slightly compressed position between the adjacent surfaces of the legs 73 and cross members 68. Stop members 77 hold the parts in place relative to the plates 68 and 67. Further, the plates 67 are provided with enlarged openings 78 which are adapted freely to pass the tubes 74. I

The opposite surfaces of the legs 73 of the members 71 may be provided with replaceable rubber-like pads 79 which actually engage the ornate surface of the parts to be passed through the apparatus.

It will be understood that by multiplicity" of work engaging holddown and propelling means carried by the chains, I means that for every appreciable length and width of the part to be fed the holddown members are numerous enough to adapt to the contour of the surface of the part of be fed. By way of example, in a machine in which the shafts 56 and 5 8 are 6 feet on centers, and the sprockets 62, 63 are approximately 2 feet in diameter, and in which the machine is approximately 44 inches wide, there are approximately 1,000 of the units comprised of the pads 79 and their supporting and guiding structures. Again, and by way of specific example the L-shaped members 71 may have legs which are 2 inches wide, and 4 inches long. Thus, each of the pairs of pads shown in FIG. 8 present to the work piece a square area of approximately 8 inches.

While the shaft 56 may be driven in any suitable fashion, 1 may mount on top of the section 33 an electric motor 81 which drives a gear box 82 through a suitable belt and pulley arrangement shown particularly in FIG.

Also, and while there may be several forms of arbors 14 for mounting the sanding drum to I illustrate in FIGS. 10, 11 and 12 a form of such device which is satisfactory. Thus, the arbor may be supported on a shaft 83 having a threaded section 84 adjacent one end. Centrally, the shaft is square as shown at 86 and is provided with four keys ways 87 in each of the square surfaces. Tapered keys 88 have their fiat surfaces engaged in the key ways 87 and their tapered surfaces engaged in longitudinally tapered slots 89 carried in the inner surfaces of wedge blocks 91. The blocks 91 have arcuate outer surfaces as shown in FIG. 11, thus to accommodate the inner surface of the sanding sleeve 16.

The keys are provided with internal grooves 92 at their thicker ends. A nut 93 received on the threaded section 84 is machined to fit into the notches 92 of the keys. Thus, when the nut 93 is run up on the threaded section 84 the blocks 91 expand outwardly, firmly engaging the inner surface of the sanding sleeve 16, holding-it firmly on the arbor. Reverse rotation of the nut 93 will withdraw the keys due to the interlocking arrangement illustrated in FIG. 10.

From what has been described it will be seen that with the machine constructed and arranged as set forth the parts to be sanded on their rear surfaces are fed into the apparatus from right to left as viewed in FIG. 1 in the direction of arrow A. Having set the depth of cut to be taken by rotating the hand wheel 24, whereby table 17 is lowered relative to the top of the sanding drum 16, the part is engaged by the rows of feeding, holddown and propelling members, being contacted first by the forward edge of the leading pad 79. This is due to the converging opening arrangement between the general level of the pads as they progress inwardly toward the table 17 as clearly shown in FIG. 1. The irregular or ornate upper surface of the part to be smoothed is thus engaged by the pads 79, which freely move upwardly due to the spring arrangement shown, permitting the under surface to be brought into plane configuration as it passes over the sanding drum 16. It will also be noted that although each of the pad supporting structures is mounted by a single bolt, these units cannot rotate about the bolt because of the close clearance between the upper section of the legs 72 of the unit 71 and the adjacent sides of the plates 67. The work piece is thus fed accurately, smoothly and under good control through the machine while the work is being performed. Furthermore, extremely uniform pressure is obtained over the entire general area of the work piece, due to the large number of the holddown and feeding members and due particularly to the use of the long springs 76, the length of which is permitted due to the particular arrangement of the tubes 74 to receive the springs. In other words, without the tubes 74 the spring could only extend between the leg 73 of the member 71 and the adjacent surface of the plate 67, thus resulting in a very short travel. As shown, however, each of the units is free to move through a relatively large range of movement, resulting in a more efficient and a softer" holddown, preventing injury to the parts.

In actual practice my invention has proven to be entirely satisfactory.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What I claim is:

l. For use in feeding work pieces to a planer or the like comprising,

a. a pair of spaced apart parallel chains supported for travel in unison,

b. a plurality of transverse members each comprising a pair of parallel portions carried by the chains and spanning the space between them,

c. a plurality of work piece engaging and feeding assemblies carried by each transverse member, each said assembly comprising: I l. a member having an enlarged foot-like work piece engaging end,

2. one of said pair of parallel portions of the trans verse members being spaced further from the foot-like work engaging piece end than the other,

members and effective to bias the work piece I members toward the work piece, and

6. pads of friction material on the foot-like work piece engaging end of said work piece members disposed to contact the work piece.

2. Apparatus as defined in claim 1 in which each said foot-like work piece engaging member is in the form of an L-shaped plate, one leg of which carries said pads on the outer surfaces thereof and the other leg of which projects away from the work piece engaging end and lies alongside but spaced from the transverse side of the ones of said transverse members closest to said work engaging ends, whereby the work piece members when supported by said rod-like members are held against rotation by said leg engaging the side of said transverse members.

3. A sub-assembly for use with a plurality of like subassemblies in holding down and feeding a work piece to a tool disposed to operate upon the surface of a work piece opposite said sub-assemblies comprising,

a. a generally L-shaped plate, one leg of which lies generally parallel to the upper surface of the work piece,

b. a rod-like mounting member secured to the upper surface of the leg described in (a) above,

c. a length of tube surrounding the mounting member and secured to said surface of said leg,

d. a carrier for said sub-assembly in the form of upper and lower spaced apart plate-like members,

e. said rod-like mounting member passing slidably through the uppermost of said plate-like members I leg of said L-shaped plate lies alongside but spaced from the lowermost of said plate-like members, thus to 

1. For use in feeding work pieces to a planer or the like comprising, a. a pair of spaced apart parallel chains supported for travel in unison, b. a plurality of transverse members each comprising a pair of parallel portions carried by the chains and spanning the space between them, c. a plurality of work piece engaging and feeding assemblies carried by each transverse member, each said assembly comprising:
 1. a member having an enlarged foot-like work piece engaging end,
 2. one of said pair of parallel portions of the transverse members being spaced further from the foot-like work engaging piece end than the other,
 3. rod-like members slidably passing through said portions of the transverse member,
 4. said work piece members being carried on the ends of the rod-like members,
 5. a compression spring surrounding the rod-like members and effective to bias the work piece members toward the work piece, and
 6. pads of friction material on the foot-like work piece engaging end of said work piece members disposed to contact the work piece.
 2. one of said pair of parallel portions of the transverse members being spaced further from the foot-like work engaging piece end than the other,
 2. Apparatus as defined in claim 1 in which each said foot-like work piece engaging member is in the form of an L-shaped plate, one leg of which carries said pads on the outer surfaces thereof and the other leg of which projects away from the work piece engaging end and lies alongside but spaced from the transverse side of the ones of said transverse members closest to said work engaging ends, whereby the work piece members when supported by said rod-like members are held against rotation by said leg engaging the side of said transverse members.
 3. A sub-assembly for use with a plurality of like subassemblies in holding down and feeding a work piece to a tool disposed to operate upon the surface of a work piece opposite said sub-assemblies comprising, a. a generally L-shaped plate, one leg of which lies generally parallel to the upper surface of the work piEce, b. a rod-like mounting member secured to the upper surface of the leg described in (a) above, c. a length of tube surrounding the mounting member and secured to said surface of said leg, d. a carrier for said sub-assembly in the form of upper and lower spaced apart plate-like members, e. said rod-like mounting member passing slidably through the uppermost of said plate-like members and said tube passing slidably through the lowermost of said plate-like members, f. a compression spring surrounding the rod-like member with its ends abutting the underside of the uppermost plate-like member and the upper surface of said leg to which the rod-like member is fixed, and g. means to hold the rod-like members slidably captive relative to the upper plate-like members.
 3. rod-like members slidably passing through said portions of the transverse member,
 4. said work piece members being carried on the ends of the rod-like members,
 4. Apparatus as defined in claim 3 in which the other leg of said L-shaped plate lies alongside but spaced from the lowermost of said plate-like members, thus to hold said L-shaped member against rotation.
 5. a compression spring surrounding the rod-like members and effective to bias the work piece members toward the work piece, and
 6. pads of friction material on the foot-like work piece engaging end of said work piece members disposed to contact the work piece. 